A new survey of data center users predicts a sharp drop in mainframe usage, though some industry analysts say the results seem unlikely.

The survey was carried out by Afcom, one of the best-known groups representing data center workers. Afcom asked about a range of topics and got responses from 436 data centers, mostly commercial facilities in the U.S. but including some government and university sites, as well as several dozen data centers overseas.

Forty percent of the data centers surveyed said they still operate mainframes today, and the median number of mainframes at those facilities is two. Of those using mainframes, 46 percent, or almost half, said they're considering replacing one or more of them in the next two years.

About two-thirds expect to replace them with a new mainframe. The part that looks bleak for mainframe vendors is that the rest (32.9 percent) said they would replace the mainframe with a different type of high-end system, presumably a Unix server or other resilient type of system.

Afcom also found that of the data centers not using mainframes today, 38 percent said they did have a mainframe 10 years ago, and just over a quarter -- 27 percent -- had one five years ago.

Predicting the mainframe's demise has been a popular sport in the IT industry, especially with the emergence of more powerful and reliable Unix servers during the 1990s. Most of the predictions turned out to be exaggerated or wrong.

"Does the mainframe decline in the long run? Yeah, probably, but one of the big surprises of the last 10 years to most people outside of IBM is how strong the mainframe has remained," said Illuminata analyst Gordon Haff.

"The numbers in this survey strike me as unbelievably high," he said. "To have almost half of data centers saying they'll replace one or more of their mainframes over the next two years, that's a strikingly high number. High-end systems in general don't turn over that quickly."

Analyst Dan Olds of Gabriel Consulting agreed. "To find that almost half the sample plans to replace their mainframe in the next year or two just doesn't seem to jibe with reality," he said.

For sure, mainframe sales have been hurt by the recession. IBM, the biggest seller of mainframes, said revenue from its System z line dropped 26 percent in the third quarter from a year earlier. But a spokeswoman said its System z revenue has increased in eight out of the past 14 quarters, and that it jumped 34 percent in the second quarter last year after the introduction of the new System z10.

The survey results may have been affected by who answered the questions, Haff suggested. "Someone could have said, 'Oh yeah, we have a mainframe over there that's likely to be replaced soon,' but it doesn't mean they're necessarily qualified to answer the question," he said.

Other results in the survey suggest a need for tighter security against cyber terrorism, Afcom said, noting publicized attacks in recent years against government Web sites in the U.S., Australia, Estonia, Romania, Georgia and elsewhere.

Almost two-thirds of the data centers surveyed said they recognize cyber terrorism as a threat, but only a little over a third include it in their disaster recovery plans, and a little over a quarter address it in their policies and procedural manuals.

Seventeen percent of those surveyed said they do not perform security background checks on new employees, "even though they will be working directly with personal, financial and even military records that could have catastrophic effects on individuals, the economy and the country's security," Afcom said.

Other findings included the following:

-- Only 15 percent of those surveyed said they are using "cloud computing," though the survey didn't define the term. The most widely used "emerging" technologies are virtualization (73 percent of respondents), Web applications (70 percent) and automation (54 percent).

-- 60 percent of respondents expect to need more space in the next five years. Of those, one third expect to expand an existing facility, 30 percent will use a new facility, 22 percent will use a collocation center, and 14 percent will use managed hosting services. 11 percent expect to use a "data center in a box," a mini-data center packed in a shipping container.

-- 71 percent of respondents are "greening" their data centers, about level with last year's Afcom survey. Of those not doing energy-efficiency projects, 40 percent said they can't afford to buy more power-efficient equipment and 30 percent blamed "procrastination."

-- 61 percent of data centers are in the process of, or seriously considering, consolidating one or more of their data centers, which was seen as a cost-cutting move in response to the recession. Just over half will move the consolidated data center to a new facility or another existing facility.

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